... To investigate this, astronomers used the Hubble Space Telescope to image several young planetary nebulae. These nebulae are the outer envelopes of stars like our Sun that have recently been cast away to space, leaving behind a core fading to become a white dwarf. ... The center of our Galaxy is a busy place. ... In infrared light, however, dust glows more and obscures less, allowing nearly one million stars to be recorded in the above photograph. ... Sometimes lightning occurs out near space. ...